1. Field of the Invention
The invention relates to glide devices and particularly to glide plane models and toys that are either elastic-driven or hand-launched.
2. Description of the Prior Art
In the development of elastic-driven and hand-launched glide devices, of chief concern has been the problem of launching such a device in a manner so as to drive it to a desirable altitude from which it may begin a lengthy and interesting glide descent. The conventional form of the glider is of fixed-wing configuration with a fuselage which adds undesirable weight and contributes parasitic drag to the flight characteristics. This conception of a glider has proven inadequate due to the excessive lift acting on such a device at high launch speed, the high lift characteristics being required when the device slows down to its normal glide speed. The high initial speed necessary to launch a glider to a desirable glide altitude tends to drive such device into either a tight loop or a stall which makes for an undesirable flight pattern. In addition, since there is not usually a load carried by such device, the usual necessity for a fuselage in an aircraft is not present, and the added weight and parasitic drag contributed by the fuselage are unnecessary inefficiencies. Examples of such fuselage-bearing fixed-wing devices are disclosed in U.S. Pat. Nos. 1,852,807, Jacobs; 2,298,425, Shaffer; and 2,274,208, Mull. On the other hand, nongyrational flying wings bearing no fuselage have thus far been impracticable due to the problem of excessive lift at launch.
Attempts to develop a device which adjusts to both high speed launch and normal glide speed conditions have thus far been simplistic two-stage affairs. U.S. Pat. No. 2,820,322 to White discloses a device wherein a fuselage-bearing glide device has a stablizer with a sliding weight which brings the stabilizer to one of two positions for either ascent or descent. The device does not address the problem of wing lift at launch. There have been a number of glide devices developed having wings which may be pulled back along the sides of a fuselage-bearing device into a diminished lift position for either an elastic-driven or hand-hurled launch. As the maximum attainable altitude of these devices is reached and their air speed diminishes, the wing assemblies of these devices are brought back into a standard fixed-wing position by either elastic or spring-driven means. The actual glide pattern of these devices after reaching glide altitude is similar to that of a fixed-wing glider being dropped from a high altitude, there being nothing particularly novel or unexpected about their flight pattern. Once again, the added weight and parasitic drag contributed by the fuselage are undesirable inefficiencies, and additional weight and parasitic drag are contributed by the elastic or spring-driven wing-opening means. Such devices are disclosed in U.S. Pat. Nos. 2,417,267, Porter; 2,221,012, Walker; 2,078,374, Drobniewsky; 2,158,377, O'Hare; 3,408,767, Anderson; 3,369,319, Brown; 3,913,657, Leckie; and 3,839,818, Heggedal.
U.S. Pat. No. 3,222,817 to Brandstetter discloses a device wherein the wings are folded up relative to the fuselage at launch rather than being folded back, and then are pulled down by elastic means into a standard fixed-wing configuration when the device reaches its maximum height. U.S. Pat. No. 4,324,064 to Bettencourt discloses a device wherein the fuselage folds in half at launch and the wings are brought down together into a sort of rudder. The wing assembly of this device is also snapped back into a standard fixed-wing configuration by elastic means once the device has ceased its climb.
A device bearing a wing assembly which is adjustably fixed before launch and remains fixed during and after launch is disclosed in U.S. Pat. No. 3,916,560. Since it does not adjust to variance in launch and flight conditions, it offers no advantage over the problem at hand.
Devices which are ballistically driven to a desired altitude and then commence an autorotational descent are disclosed in U.S. Pat. Nos. 2,899,773, Lockwood; 2,753,657, Taggart; and 3,119,196, Alberico et al. Devices which are given a rotational impulse at launch and which consequently gyrate throughout their flight pattern are described in U.S. Pat. Nos. 2,837,077, Frazelle, and 3,559,331, Eller. Since these are rotary wing aircraft depending on gyration rather than forward air speed to develop lift, they do not constitute part of an analogous art.
Devices intended to drive an unopened parachute toy to a desirable altitude where it may then open and begin its descent are described in U.S. Pat. Nos. 3,172,231, Arland, and 2,587,699, Cotter. Again, these devices are not part of an analogous art.
Applicant is not aware of any glide device in the prior art which is capable of absorbing landing or crash impact. Consequently, all previous hand-launched glide devices have concentrated impact in such a way as to damage or destroy the device or cause damage to the object of impact, which may mean bodily harm when such a device strikes a person.
Applicant is not aware of any elastic-driven or hand-launched airplane glider device which is capable of aerodynamically adjusting to the difference between launch and glide conditions without depending upon additional spring or elastic means, or has been capable of adjusting to the varying flight conditions after glide has been established, or has been capable of absorbing the shock of impact. Applicant is aware of no elastic-driven or hand-launched glide device or flying wing wherein the relative wing geometry is not fixed at any point during flight.